Recently, the “3,000 tons/year Isosorbide Complete Technology” jointly developed by Shanghai DODGEN Chemical Technology Co., Ltd. and Puyang Shengtong Juyuan New Material Co., Ltd., successfully passed the scientific and technological achievement appraisal organized by the China Petroleum and Chemical Industry Federation (CPCIF). The appraisal committee unanimously agreed: This technology has reached an internationally advanced level.
Focusing on the key bottlenecks in the large-scale preparation of polymer-grade isosorbide, DODGEN has constructed a complete engineering technology system for green synthesis and high purification, successfully forging a continuous production technology path for high-end bio-based monomers.
Solving Industry Core Problems: From “Highly Corrosive Batch” to “Green Continuous” Processes
As the only rigid bio-based diol currently achieving industrialized production, isosorbide is a crucial structural monomer for materials such as bio-based polycarbonates (PC) and bio-based polyesters. However, for a long time, the industry has predominantly relied on the traditional sulfuric acid batch process, which presents several major issues:
- Severe strong acid corrosion, resulting in high equipment investment.
- Complex side reactions, leading to high product color and significant purity fluctuations.
- Difficulties in continuous scale-up, resulting in relatively low yields.
- High treatment costs for waste acid and wastewater.
These issues have directly restricted the stable supply of polymer-grade products and caused long-term reliance on imports for high-end applications.
Recognizing the domestic gap in key monomer technologies and the urgent needs of partners in the polycarbonate industry chain, DODGEN, together with Shengtong Juyuan, initiated this project. Targeting “continuous, green, and high-purity” objectives, DODGEN entirely reconstructed the isosorbide preparation and purification technology system.
Key Technological Breakthroughs: Building a Full-Process Engineering Technology System
This collaboration successfully developed a complete isosorbide technology with independent intellectual property rights, culminating in the construction of a 3,000-ton industrial plant. Certified by the appraisal committee, this technology has achieved major breakthroughs in three areas:
- Innovation in Catalytic Systems
The process adopts an independently developed novel mild catalyst, completely replacing highly corrosive sulfuric acid, p-toluenesulfonic acid, and hard-to-recover solid acids. This achieves lower capital investment, enhanced reactivity, and high compatibility with continuous production.
- Significantly reduces equipment corrosion.
- High reactivity with fewer side reactions.
- Highly compatible with continuous processes.
- Breakthroughs in Precision Analysis
By introducing a calcium-based sugar column and a Refractive Index Detector (RID), the team overcame the challenges of separating sugar alcohol impurities. They established a High-Performance Liquid Chromatography (HPLC) analysis method for the absolute content of isosorbide, providing a highly accurate “eagle eye” for process control.
- Leap in Green Purification
An innovatively constructed coupled process: Distillation Separation + Dynamic Melt Crystallization High Purification.
- Energy consumption is only 20%-40% of traditional solvent crystallization.
- Zero solvent introduction throughout the entire process.
- Significant reduction in “three wastes” (emissions) discharge.
- Product purity ≥ 99.5%.
- Color grades fully meet electronic-grade and polymer-grade application requirements.
Technology Platform Capabilities: Beyond a Single Product Breakthrough to Industrial Delivery
DODGEN’s original intention was clear: to develop a mass-production technology for polymer-grade isosorbide that is both economically viable and possesses complete independent IP rights. This is not just about solving a monomer production problem; it is about connecting the entire bio-based industry chain from “corn” to “high-end engineering plastics.”
The development of the kiloton-scale isosorbide industrial plant included process route design, material balance, and equipment selection. Key equipment selections included: continuous falling film reactors, molecular distillation, falling film reboilers for high-viscosity heat-sensitive materials, ultra-high vacuum distillation columns, and dual-falling-film melt crystallization units.
The significance of this project lies not only in a single product breakthrough but in verifying and establishing DODGEN’s:
- Continuous engineering scale-up capability for bio-based monomers.
- High purification technology capability for complex sugar alcohol systems.
- Complete technology export and industrialization delivery capability.
- Monomer-polymer synergistic design capability.
This marks DODGEN’s robust, systematic engineering capability in the field of core monomers for bio-based materials—from laboratory R&D straight through to industrial implementation.
Driving Domestic Substitution: Breaking Through Upstream Bottlenecks of High-End Bio-Based Materials
Polymer-grade isosorbide has long been monopolized by overseas enterprises. The successful application of this technology:
- Fills the domestic gap in continuous polymer-grade production.
- Enhances supply chain security and independent controllability.
- Reduces the manufacturing cost of high-end bio-based PC.
- Provides key raw material support for downstream fields such as optics, medical devices, and electronics.
This is more than a technological breakthrough; it is a crucial step forward in upgrading China’s bio-based materials industry chain.
For years, DODGEN has deeply cultivated the fields of bio-based materials and high-end monomer engineering technologies. Centered around the directions of “low-carbon, continuous, and high-purity,” DODGEN continuously provides customers with highly competitive complete solutions, empowering the high-quality development of China’s new chemical materials industry.
